1.APPLY TO ALL DRILLS : 8 pieces screw extractors work with any drill and all the screw size or bolt, These extractor tools are used to reverse the damaged screw counterclockwise until it is releasedPOWERFUL : Stripped screw extractor removes even the most stubborn stripped, damaged, embedded, rusted and painted-over screws and bolts2.EASY TO USE : Firstly, using drill clockwise select a drill bit (burnished side) smaller than the damaged screw and drill down into head of screw/bolt to make a clear hole. Then flip the tool to extraction part (spiral side) and switch drill to counter clockwise by applying constant & slow pressure onto screw head. Follow these simple steps to get the job done. Please note: Move the drill at a very low speed, an oil coating is added to the tool to prevent rusting.